The disclosure relates to a circuit breaker.
In general, a circuit breaker is a device for maintaining safety by blocking a circuit in an abnormal state such as an overload or a short circuit. That is, when a current exceeding a rated current flows through an electric circuit, the circuit breaker performs a function of blocking the current flow in order to protect a worker.
Hereinafter, a circuit breaker will be described with reference to accompanying drawings.
FIG. 1 is a perspective view showing a circuit breaker according to the related art.
Referring to FIG. 1, the circuit breaker 1 includes an upper outer box (refer to reference numeral 20 in FIG. 2) which defines an upper appearance, a lower outer box 10 which defines a lower appearance, and an inner box 30 disposed in the upper and lower outer boxes 20 and 10. When a user operates a switch lever to control an operation of the circuit breaker 1, fixed and movable contactors placed in the circuit breaker 1 are separated from each other, so that a high-temperature thermal arc is generated between both contactors. The arc damages an electric conductor and a forming component in the circuit breaker 1. Therefore, there is a need to rapidly exhaust the arc generated in the circuit breaker 1 to an outside.
FIG. 2 is a view showing an exhaust port structure of a load part of a circuit breaker according to the related art.
Referring to FIG. 2, the exhaust port structure of the load part of the circuit breaker includes an inner box 30, a load part arc exhaust port 12 connected to the inner box 30, an arc guide part 14 for guiding a movement of an arc passing through the load part arc exhaust port 12, and an arc passage forming part 13 for providing an passage through which an arc guided by the arc guide part 14 is exhausted. The acr guide part 14 is inclined upward about a horizontal direction such that the arc guide part 14 may be connected to a load part arc passage 15.
The arc passage forming part 13 includes the load part arc passage 15 for providing an exit and entry passage of an arc and a protrusion part 11 adjacent to the load part arc passage 15. The protrusion part 11 may include a plurality of inclined parts 11a and for example, may have a shape of a trigonal prism.
A moving path of the arc generated from the load part of the circuit breaker 1 is as follows.
An arc initially generated from the inner box 30 of the circuit breaker 1 passes through the load part arc exhaust port 12 and the arc, which passes through the load part arc exhaust port 12, passes through the load part arc passage 15 along the arc guide part 14 to be exhausted to an outside of the circuit breaker 1.
However, since the load part arc exhaust port 12 is spaced apart from the load part arc passage 15 and a configuration of continuously guiding the arc exhausted from the load part arc exhaust port 12 into the load part arc passage 15 does not exist, the arc, which passes through the load part arc exhaust port 12, is not rapidly exhausted to an outside of the circuit breaker 1 so that voltage leakage and reverse current phenomenons occur in the circuit breaker 1.
FIG. 3 is a view showing an arc exhaust structure of a power source part of a circuit breaker according to the related art.
Referring to FIG. 3, the arc exhaust structure of the circuit breaker includes an inner box 30, a power source arc exhaust port 25 connected to the inner box 30, a power source arc passage forming part 22 for guiding a movement of an arc passing through the power source arc exhaust port 25.
The power source arc passage forming part 22 includes a passage guide part 22a having a round shape and a passage inclined part 22b connected to the passage guide part 22a and inclined at a predetermined angle. An arc may be exhausted into an outside of the circuit breaker 1 through a power source arc passage 21 which is an inner space in which the passage guide part 22a and the passage inclined part 22b. 
A moving path of the arc generated from the power source part of the circuit breaker 1 is as follows
An arc initially generated from the inner box 30 of the circuit breaker 1 passes through the power source arc exhaust port 25 and the arc, which passes through the power source arc exhaust port 25, passes through the power source arc passage 21 to be exhausted into an outside of the circuit breaker 1.
However, since the power source arc exhaust port 25 is spaced apart from the power source arc passage 21 and a configuration of continuously guiding the arc exhausted from the power source arc exhaust port 25 into the power source arc passage 21 does not exist, the arc, which passes through the power source arc exhaust port 25, is not rapidly exhausted to an outside of the circuit breaker 1, so that voltage leakage and reverse current phenomenons may occur in the circuit breaker 1.